Codebook searching for 4.8 kbps CELP speech coder

Abstract

The authors describe an implementation of fast algorithms for codebook searching used in code-excited linear predictive (CELP) speech coding. They present details of the algorithms including (i) fast conversion of line spectrum pair parameters to linear predictive coding parameters, and (ii) fast searches of the parameters of adaptive and stochastic codebooks. The description can be readily used for CELP implementations, such as on (i) high-quality low-bit-rate speech transmission in point-to-point or store-and-forward mode, and (ii) efficient speech storage in speech recording and multimedia databases. The algorithms have been implemented on an IBM-PC AT equipped with a TMS320C30 module and a SUN Sparcstation 10 for the development of packet radio speech transmission and voice mail applications, respectively.<>